Since the h-index was first introduced to the scientific community by Jorge Hirsch in 2005 (Hirsch JE. An index to quantify an individual’s scientific research output. Proc. Natl. Acad. Sci. 2005; 102(46): 16569-16572.), there has been no shortage of skeptics angrily waving their torches and pitchforks in protest. And it’s no wonder why – telling a scholar that you’re going to assign an index to measure the impact and productivity of his published work is like telling a parent that you’re going to assess the value of his baby. You’ve likely heard all the arguments against the h-index before, but let’s recap just a few:
- It awards all co-authors on a given paper with the same value, from the lead author down to the very last contributing author on the list.
- It suffers from a case of reverse ageism – the older an author is, the higher his h-index is likely to be.
- Using it to rank authors across disciplines is about as useful as comparing apples to oranges.
The list of criticisms goes on, but let’s not fail to mention that even the way it’s calculated is so simplistic that it seems like something my eight year-old nephew came up with (just kidding – he’s actually four.)
But as much as people like to poke holes and poke fun at the h-index methodology, the Carrie Bradshaw in me couldn’t help but wonder who is really getting the last laugh. After all, if the h-index is so flawed, then why is it still a topic of heated conversation almost ten years later? I had to sift through countless negative articles, angry blog posts, and borderline death threats, but eventually found some surprising revelations around how the scientific community is embracing one little number in four big ways.
- Measuring research performance. It’s common knowledge that using h-index to compare research output across different disciplines isn’t fair to more specialized fields. However, some global university ranking systems are beginning to incorporate the h-index into their methodology at the subject level. The most notable of these is the QS World University Rankings by Subject, which started factoring it into their calculations in 2013. Other world university rankings that now utilize the h-index include the University Rankings by Academic Performance, the National Taiwan University Ranking, and the Center for World University Rankings.
- Grant funding. From Ophthalmology (Svider PF et al. The association between scholarly impact and National Institutes of Health funding in ophthalmology. Ophthalmology. 2014; 121(1): 423-428.) to Academic Radiology (Rezek I et al. Is the h-index predictive of greater NIH funding success among academic radiologists? Acad Radiol. 2011; 18(11): 1337-1340.) to Acta Anaesthesiologica Scandinavica (Pagel PS, Hudetz JA. H-index is a sensitive indicator of academic activity in highly productive anaesthesiologists: results of a bibliometric analysis. Acta Anaesthesiol Scand. 2011; 55(9):1085-9.) , studies published in a variety of peer-reviewed, multidisciplinary journals have reported that a higher h-index is correlated with obtaining grant funding. World Neurosurgery even found that h-index is the only bibliometric that is predictive of receiving funding from the National Institutes of Health, the preeminent funding body in the United States.
- Tenure and promotion decisions. Hirsch himself suggested that certain h-index values could lead to career advancement to associate professor or full professorship at major research universities. While this metric certainly isn’t the be-all and end-all in promotion criteria, it does seem to carry some weight in formal evaluation. The School of Medicine at the University of Maryland and Ohio State University are just a couple examples of institutions that were found to reference the h-index in their guides to the promotion and tenure process.
- Self-promotion. Faculty members at major universities on every continent were found to tout their personal h-index rankings alongside other awards and qualifications in their online biographies, LinkedIn profiles, and resumes. Could it be that authors are having a change of heart about the h-index? That may be an overstatement, but they do seem to be admitting (perhaps begrudgingly) that it has become a widely recognized and influential bibliometric in the scientific community. Love it or hate it – it appears the h-index is here to stay.
What are your feelings about the h-index? Have you seen it used in any of these (or other) ways? Leave us a comment below or tweet @WileyResearcher
About the AuthorMore Content by Rachel Zawada